Decided to "push my envelope" today and go climbing. At about -15 F. Really, a nice sunny day with very little wind - just happened to be about 25 degrees colder than my previous coldest climb. Picked a familiar aspen tree just a little ways into the woods from my house.

Dressing up: I've gotten to really like Duofold long underware for winter activity, the stuff with a thin _layer_ of polyester against the skin and a wool-poly _layer_ over that. Thick wool/synthetic socks. A polyester pile jacket. A coverall over all of that; when _layer_s coming untucked in the middle of a climb, having skin exposed on back and stomach is distracting. Sorels (thick insulated boots), lined gloves, a Mad-Bomber hat, and a beard (there's a reason more guys wear beards in the north). This worked fine - I had scarf and winter jacket along just in case, but never used them. Being acclimated helps; I've been outside a lot this winter, mostly just for walks.
Oh, one other detail: if you're a male outside at below zero temperatures for very long, a bit of extra insulation over the groin area is helpful.

Tree entry: I'm still impressed that Zing-It throwline doesn't stiffen up more in the cold. It's only a little more prone to throw tangles than in the summer. Only problem was a throwbag ring lodging on a branch stub - actually snapped the Zing-It trying to get it down (never thought I'd do that; maybe the stuff is a little weaker in the cold...). Eventually hit a good TIP but then the next problem came up. Su Sleeves REALLY don't like this kind of cold; the covering gets brittle and cracks, and the sleeve wants to keep sliding off the branch after it's set. The _meta_l inside is unaffected, so it's not a safety issue, but I'm going to have to go back to my leather sleeves for these conditions.
Other than these annoyances, the main problem in all of this was maintaining manual deterity. Body core temperature was fine, but bare fingers (I can't toss a throwbag wearing gloves) chill fast, and bare fingers touching anything aluminum chill INSTANTLY. However you _layer_ up, leaving your neck open enough to be able to put your hands against your neck (or, better, jam them into your armpits) is really helpful.

Climbing: Climbing was pretty much as usual. Since I couldn't grip the rope very well with lined leather gloves, I used my old "training wheels" rig of microcender+footloops for the first 15 feet. Wasn't sure that single footlocking the tail (my usual way of DdRT once I have a bit of rope under me) would work with big fat round Sorel boots, but it was fine. Not too warm or too cold. Crystal clear blue sky and bright snow all over the ground. Didn't hang out as long as usual, and didn't hassle with a second pitch (not a lot farther to go in that tree anyway - the first pitch was near the top), but it was nice up there.

On the whole, not a bad climb.

When I got back, for some reason Wendy didn't want a kiss while I still had ice all over my beard...